1. Field of the Invention
The present invention relates to a multi-layer printed circuit board, and more particularly, to a multi-layer printed circuit board having improved electrical properties.
2. Description of the Related Art
A PCB (printed circuit board) generally includes 6 signal layers and insulating layers respectively arranged between the signal layers.
Electrical properties of the multi-layer printed circuit board include impedance matching, EMI (electro-magnetic interference), cross-talk, ringing, glitch, timing, decrease of SSN (simultaneous switching noise), unwanted coupling, and skew.
The electrical properties change according to a thickness of each of the insulating layers included in the multi-layer PCB, a width of a pattern formed on the signal layer, and an interval between the patterns, and the electrical properties are independent of one another. Therefore, when one of the electric properties is enhanced, another may worsen.
Accordingly, the multi-layer PCB needs to be configured to satisfy the aforementioned electric properties by optimizing the thickness of the insulating layer comprised in the multi-layer PCB, the width of the pattern formed on the signal layer, and the interval between the patterns which influence the electric properties.